Eye exams are an important part of maintaining good overall eye health. Having regular eye exams is a critical component in detecting eye diseases or problems in their early stages when they are often still treatable.
With regular eye exams the doctor can sometimes detect a problem before any noticeable symptoms begin to occur. Eye exams are necessary to prescribe proper corrective lenses or contacts, but can also serve a more specialized purpose, such as determining eligibility for laser refractive surgery, or monitoring an eye condition. Regular eye exams are the key to preserving good vision for life.
Common Tests & Evaluations during an eye exam
Questions about a patient’s medical history and eye health history are asked by a technician and further more specific questioning is asked by the doctor.
The doctor inspects all outward visible parts of the eye and surrounding tissue.
The patient’s pupils will be inspected for equal size and regular shape along with how they react to light.
Eye muscle health and mobility
Eye movement is checked in six directions (corresponding to the six extraocular muscles), as well as tracking a moving object (such as a pen).
The patient covers one eye at a time, and with the other eye gazing straight ahead, identifies objects in peripheral vision (often simply the number of fingers the doctor is showing.)
A common means of measuring visual acuity is the Snellen chart. This is a large card or projection with progressively smaller horizontal lines of random block letters. The test determines how well a patient can discern detail at a given distance. Patients taking this test will cover one eye and then read aloud the letters of each row, starting from the top. The smallest row that can be accurately read indicates the patient’s visual acuity in that eye.
This test is used to find the best corrected vision, if necessary for prescription eyewear or contacts. The doctor will try various lenses in front of each eye, as the patient focuses on a chart at a distance or up-close, to help determine the best power of correction.
The doctor shows the patient a series of images with symbols embedded in color dots or patterns. Based upon the patient’s ability to identify the symbols, certain types of colorblindness can be diagnosed or ruled out.
This test is often done with a slit lamp ophthalmoscope, an instrument with light and magnifying lenses. Alternatively, the doctor may use other means, such as an indirect ophthalmoscope for wider viewing of the retina. Ophthalmoscopy aims to inspect the retina and surrounding internal eye. This test can help diagnose problems with the retina or detachment of the retina, and monitor diseases like glaucoma and diabetes. An opacity in the lens of the eye can indicate a cataract. Sometimes the doctor will dilate the pupils with eye drops, to gain a wider view of the internal eye.
This test measures intraocular pressure, which can be a sign of glaucoma if pressure is abnormally high. Instruments that gently touch the eye are used to accurately measure the pressure.